Banca de DEFESA: NAYARA CELY FERREIRA COÊLHO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : NAYARA CELY FERREIRA COÊLHO
DATE: 18/08/2023
TIME: 08:00
LOCAL: Auditório do Departamento de Química
TITLE:

LEVAN: FROM THE DEVELOPMENT OF NEW METALLOPHYRIC DRUGS TO THE ELUCIDATION OF IN VIVO ACTION MECHANISMS USING QUANTUM DOT AS A BIOLOGICAL MARKER

KEY WORDS:

Cancer, ruthenium complexes, levan, antineoplastic agents, quantum dots

PAGES: 123
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Química Bio-Inorgânica
SUMMARY:

Levan is a fructose exopolysaccharide that presents functional characteristics in the human organism, such as hypolipidemic and antitumor action. Due to these characteristics, the present work aims to produce levan and its chemical modification in order to optimize its antitumor properties, based on ruthenium; and to propose mechanism of action through biological marking, using quantum dots in in vitro assays. The methodology was divided into three chapters, the first of which consisted of the production and chemical modification of levan. The second chapter described the labeling of the levan matrix with quantum dots, in order to propose the mechanism of action in vivo. In the third chapter, the modification of levan with ruthenium was described and its antitumor activity was tested. The oxidation of the levan matrix was performed using sodium periodate in aqueous medium. After this step, the matrix was modified with 1,2-diaminoethane and subsequently coordinated to Ru3+ ion. Infrared and NMR spectroscopy showed bands and peaks in regions characteristic of the polysaccharide structure, evidencing the formation of levan. The modification using 1,2-diaminoethane as nitrogen source was successful, evidenced by the appearance and displacement of the bands in the infrared as well as the appearance of a peak at 1.87 ppm absent in the oxidized levan thus demonstrating the presence of amino groups. The bands observed in the infrared spectroscopy of the Ru-Levana complex evidenced the coordination of the metal to the nitrogenous sites, with the displacement of the broad band of the C-N group to lower wavenumbers. The acute toxicity test of the Ru-Levana compound was classified in category 5, being considered non-toxic or of low toxicity. The antitumor activity results showed tumor inhibition values higher than the results found for the market standard (cisplatin). The labeling of levan was performed using CdTe quantum dots. The monitoring of the quantum dot preparation and labeling process was performed through the spectral shift analysis of the emission profile of the samples, which showed evidence of the interaction of the modified levan with the CdTe quantum dots.

COMMITTEE MEMBERS:
Externa à Instituição - GLÁUCIA MANOELLA DE SOUZA LIMA - UFPE
Externa à Instituição - JÉSSIKA FERNANDA FERREIRA RIBEIRO - UFPE
Interno - JOAO RUFINO DE FREITAS FILHO
Interna - ***.999.014-** - JULIANA ANGEIRAS BATISTA DA SILVA - UFPE
Presidente - MONICA FREIRE BELIAN